Table of Contents i Community-Based Technologies for Domestic Wastewater Treatment and Reuse: Options for urban agriculture by Gregory D. Rose, Centre Intern – spring 1999 International Development Research Centre, Ottawa Cities Feeding People Series – Report 27 Table of Contents TABLE OF CONTENTS .......................................................................................................................i LIST OF TABLES................................................................................................................................iii GLOSSARY .........................................................................................................................................iv EXECUTIVE SUMMARY ...................................................................................................................v PART I: SANITATION AND WASTEWATER RESOURCE RECOVERY ........................................................1 1.0 INTRODUCTION .............................................................................................................................................1 1.1 ORGANISATION OF THE REPORT............................................................................................1 1.2 TERM DEFINITIONS ....................................................................................................................2 2.0 WASTEWATER MANAGEMENT ..................................................................................................................4 2.1 THE URBAN DILEMMA...............................................................................................................4 2.2 COSTS OF (NOT) PROVIDING ADEQUATE SANITATION ....................................................5 2.3 URBAN AGRICULTURE AND WASTEWATER RESOURCES ...............................................6 3.0 PLANNING AND IMPLEMENTING WASTEWATER REUSE PROJECTS..............................................7 3.1 APPROPRIATE TECHNOLOGY ..................................................................................................7 3.2 MECHANISED VS. NON-MECHANISED WASTEWATER TREATMENT.............................8 3.3 ON-SITE SANITATION.................................................................................................................9 3.4 DECENTRALISED URBAN CATCHMENT AREAS................................................................10 4.0 PUBLIC HEALTH AND SAFETY ................................................................................................................12 4.1 EFFLUENT QUALITY STANDARDS........................................................................................12 4.2 HEALTH GUIDELINES...............................................................................................................12 5.0 INSTITUTIONAL AND COMMUNITY-RELATED ISSUES .....................................................................14 6.0 SEGREGATING URBAN WASTEWATER RESOURCES..........................................................................15 6.1 ISOLATION OF THE DOMESTIC WASTEWATER.................................................................15 6.2 INDUSTRIAL, MUNICIPAL AND DOMESTIC REUSE OF WASTEWATER........................16 7.0 INTEGRATED RECOVERY..........................................................................................................................17 7.1 ECOLOGICAL ENGINEERING..................................................................................................17 7.2 ADVANCED SOLAR TECHNOLOGY.......................................................................................19 7.3 THE MAYSARA PROJECT: INTEGRATED WASTE MANAGEMENT FACILITY..............20 PART II: SELECTED TREATMENT TECHNOLOGIES .................................................................................22 8.0 LAND-BASED TREATMENT TECHNOLOGIES.......................................................................................22 Table of Contents ii 8.1 DRY VS. WET SANITATION SYSTEM ....................................................................................22 8.2 HOUSEHOLD-LEVEL/ON-SITE TREATMENT SYSTEMS ....................................................24 8.2.1 Double Vault Batch Composting Systems..................................................................................................... 24 8.2.2 Composting Toilets and Wastewater Garden™............................................................................................ 24 8.2.3 DAFF Latrines.............................................................................................................................................. 27 8.3 ANAEROBIC TREATMENT SYSTEMS....................................................................................28 8.3.1 Upflow Anaerobic filters............................................................................................................................... 28 8.3.2 Biogas Reactors............................................................................................................................................ 29 8.3.3 Recent developments in biogas technology................................................................................................... 31 8.4 NEIGHBOURHOOD LEVEL/OFF-SITE ANAEROBIC TREATMENT SYSTEMS ................32 8.4.1 Upflow Anaerobic Sludge Blankets .............................................................................................................. 32 8.5 SOIL AQUIFER TREATMENT...................................................................................................34 9.0 WATER-BASED WASTEWATER TREATMENT TECHNOLOGIES .......................................................35 9.1 CONFINED SPACE CONSTRUCTED WETLAND TREATMENT SYSTEM.........................35 9.2 NEIGHBOURHOOD-LEVEL/OFF-SITE CONSTRUCTED WETLANDS ...............................36 9.2.1 Subsurface Wetlands..................................................................................................................................... 36 9.2.2 Free Water Surface Wetlands ....................................................................................................................... 37 9.3 FLOATING AQUATIC MACROPHYTES..................................................................................37 9.3.1 Cropping system management ...................................................................................................................... 38 9.3.2 Disease vector management ......................................................................................................................... 38 9.3.3 Water Hyancinth........................................................................................................................................... 38 9.3.3.1 Community-Based Wastewater Treatment - Castor, Senegal .................................................................... 39 9.3.4 Duckweed...................................................................................................................................................... 39 9.3.4.1 Duckweed-Based Pisci-culture: PRISM-Bangladesh ................................................................................ 40 9.3.4.2 GreenGold Corporation ............................................................................................................................ 42 9.4 WASTEWATER STABILISATION PONDS ..............................................................................42 9.4.1 Advanced Treatment ..................................................................................................................................... 44 9.4.2 Stabilisation ponds and supporting growth media ....................................................................................... 44 9.4.3 Advanced integrated ponds systems.............................................................................................................. 45 9.4.3.1 Sheaffer modular reclamation and reuse system ....................................................................................... 45 9.5 AQUACULTURE .........................................................................................................................46 10.0 SLUDGE MANAGEMENT..........................................................................................................................47 10.1 DEVELOPMENTS IN NATURAL SLUDGE DE-WATERING TECHNOLOGY...................47 10.2 SLUDGE REUSE IN EGYPTIAN AGRICULTURE.................................................................48 PART III: CONCLUSIONS AND RECOMMENDATIONS ..............................................................................50 11.0 CONCLUSIONS AND RECOMMENDATIONS ........................................................................................50 CONCLUSIONS .................................................................................................................................50 RECOMMENDATIONS.....................................................................................................................51 REFERENCES .....................................................................................................................................................54 ANNEX I: GENERAL ATTRIBUTES OF TECHNOLOGIES REVIEWED.........................................65 ANNEX II - INTERNET RESOURCES................................................................................................67 ANNEX III - IDRC PROJECTS IN WASTE MANAGEMENT (1974 - 1997)......................................68